Worldwide the consumption of clean water for drinking is increasing. Drinking water is retrieved from underground wells, but also surface water or even de-salted sea water are used as drinking water. Thus, there is a demand for utility companies to measure cleanness of the water supplied to the utility network.
A complete analysis of cleanness of water involves complicated biochemical analyses, however in some cases a measure of water quality obtained by means of a turbidity measurement can be sufficient, i.e. measurement of the amount of particles in the fluid as a measure of cleanness of the fluid. Such turbidity measurements can be based on optical methods.
Optical turbidity equipment, however, is not well-suited for functioning as a permanently mounted part of a utility network due to the forming of coatings of minerals and/or biofilms on the optical surfaces, which will disturb the turbidity measurements and necessitate frequent maintenance. Furthermore, such optical turbidity measurement equipment is expensive and can thus in practice only be installed at a limited number of positions in a utility network.